1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
castortr0y [4]
3 years ago
6

A car is traveling at a speed of 20m/s and has a mass of 1200kg how much kinetic energy does it have

Physics
1 answer:
Oxana [17]3 years ago
4 0

Answer:

Explanation:

The formula for Kinetic Energy is

KE=\frac{1}{2}mv^2. Filling in:

KE=\frac{1}{2}(1200)(20)^2 It looks like we only need 1 significant digit here but I'll give you 2 and you can round how you want.

KE = 2.4 × 10⁵ J

You might be interested in
A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75
8_murik_8 [283]

Complete Question

A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75.0 cm . The power is off for 40.0 s , and during this time the flywheel slows down uniformly due to friction in its axle bearings. During the time the power is off, the flywheel makes 210 complete revolutions. At what rate is the flywheel spinning when the power comes back on(in rpm)? How long after the beginning of the power failure would it have taken the flywheel to stop if the power had not come back on, and how many revolutions would the wheel have made during this time?

Answer:

\theta=274rev

Explanation:

From the question we are told that:

Angular velocity \omega=510rpm

Mass m=40.kg

Diameter d 75=>0.75m

Off Time t=40.0s

Oscillation at Power off N=210

Generally the equation for Angular displacement is mathematically given by

 \theta_{\infty}=\frac{w+w_0}{t}t

 w=\frac{2*\theta_{\infty}}{t}-w_0

 w=\frac{28210}{40*(\frac{1}{60})}-510

 w=120rpm

Generally the equation for Time to come to rest is mathematically given by

 t=(\frac{\omega_0}{\omega_0-\omega})t

 t=(\frac{510}{510-120rpm})(40.0)(\frac{1}{60})

 t=0.87min

Therefore Angular displacement is

 \theta =(\frac{120+510}{2})0.87

 \theta=274rev

6 0
3 years ago
Assume that block A which has a mass of 30 kg is being pushed to the left with a force of 75 N along a frictionless surface. Wha
Veronika [31]

Answer:

The force of friction acting on block B is approximately 26.7N.  Note: this result does not match any value from your multiple choice list. Please see comment at the end of this answer.  

Explanation:

The acting force F=75N pushes block A into acceleration to the left. Through a kinetic friction force, block B also accelerates to the left, however, the maximum of the friction force (which is unknown) makes block B accelerate by 0.5 m/s^2 slower than the block A, hence appearing it to accelerate with 0.5 m/s^2 to the right relative to the block A.

To solve this problem, start with setting up the net force equations for both block A and B:

F_{Anet} = m_A\cdot a_A = F - F_{fr}\\F_{Bnet} = m_B\cdot a_B = F_{fr}

where forces acting to the left are positive and those acting to the right are negative. The friction force F_fr in the first equation  is due to A acting on B and in the second equation due to B acting on A. They are opposite in direction but have the same magnitude (Newton's third law). We also know that B accelerates 0.5 slower than A:

a_B = a_A-0.5 \frac{m}{s^2}

Now we can solve the system of 3 equations for a_A, a_B and finally for F_fr:

30kg\cdot a_A = 75N - F_{fr}\\24kg\cdot a_B = F_{fr}\\a_B= a_A-0.5 \frac{m}{s^2}\\\implies \\a_A=\frac{87}{54}\frac{m}{s^2},\,\,\,a_B=\frac{10}{9}\frac{m}{s^2}\\F_{fr} = 24kg \cdot \frac{10}{9}\frac{m}{s^2}=\frac{80}{3}kg\frac{m}{s^2}\approx 26.7N

The force of friction acting on block B is approximately 26.7N.

This answer has been verified by multiple people and is correct for the provided values in your question. I recommend double-checking the text of your question for any typos and letting us know in the comments section.

6 0
3 years ago
Read 2 more answers
Is velocity a scalar or a vector
gizmo_the_mogwai [7]
Velocity<span> is a</span>vector<span> quantity; it is direction-aware.</span>
5 0
3 years ago
Read 2 more answers
In a region of space where gravitational forces can be neglected, a sphere is accelerated by a uniform light beam of intensity 8
BlackZzzverrR [31]

Answer:

The correct answer is B

Explanation:

To calculate the acceleration we must use Newton's second law

      F = m a

      a = F / m

To calculate the force we use the defined pressure and the radiation pressure for an absorbent surface

       P = I / c        absorbent surface

       P = F / A

       F / A = I / c

       F = I A / c

The area of ​​area of ​​a circle is

      A = π r²

We replace

     F = I π r² / c

Let's calculate

     F = 8.0 10⁻³ π (1.0 10⁻⁶)²/3 10⁸

     F = 8.375 10⁻²³ N

Density is

      ρ = m / V

      m = ρ V

      m = ρ (4/3 π r³)

      m = 4500 (4/3 π (1 10⁻⁶)³)

      m = 1,885 10⁻¹⁴ kg

Let's calculate the acceleration

     a = 8.375 10⁻²³ / 1.885 10⁻¹⁴

     a = 4.44 10⁻⁹ m/s²               absorbent surface

The correct answer is B

4 0
3 years ago
What is the speed of a wave if the wavelength is 100m and the period is 20s
Sergio039 [100]
I don’t think I’m right but I want to say 500 m/s
4 0
4 years ago
Read 2 more answers
Other questions:
  • Whose definition of acids and bases emphasizes the role of protons
    9·1 answer
  • Drivers a and b travel west from boston. driver a leaves three hours earlier traveling at a constant speed of 68mph. driver b fo
    15·1 answer
  • Which derived quantity might be measured in mm^3
    7·1 answer
  • A car skids to a stop. What happens to its kinetic energy?
    9·1 answer
  • What piece of sports equipment is aerodynamic
    14·1 answer
  • Which category of materials does concrete belong to and why?
    10·2 answers
  • Small-plane pilots regularly compete in "message drop" competitions, dropping heavy weights (for which air resistance can be ign
    5·1 answer
  • A UHF television loop antenna has a diameter of 11 cm. The magnetic field of a TV signal is normal to the plane of the loop and,
    15·2 answers
  • If the solar system shrank so that the sun were located just one centimeter from Earth, about how far away could you find the ne
    8·1 answer
  • When a brick is dropped from the roof of a house, it lands on the ground with a speed v. What will the speed at ground level be
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!